Why Is My Hot Tub Cloudy? How to Fix It

A hot tub is easily one of the most enjoyable backyard additions, especially after a long day’s work. But when that crystal-clear hot tub water turns cloudy, it can be a big headache that could even make you sick. Why do you have cloudy hot tub water, and how can you fix it?

There are a few reasons why you may find cloudy water in a hot tub which are:

• The sanitizer, pH, and alkaline levels need to be corrected
• The filters themselves are filthy
• A lot of debris has fallen into the tub
• It’s been used much more frequently than usual 

That’s the simple story, but troubleshooting a cloudy hot tub requires more in-depth knowledge of how everything works. Below, we will cover the common reasons you may have cloudy, hot tub water and how to fix it.

Why is my hot tub water cloudy?

When you get your swim trunks on (or not) after a hard day, the last thing you want to see is cloudy and gross water in your hot tub. It’s a headache, and the solution isn’t always obvious.

To help you properly identify the real culprit, we’ve included more details about all the different things that could be making your hot tub water cloudy.

Your hot tub “core” levels are all off

One of the most important pieces of good hot tub hygiene is making sure that the water has the proper levels of these three components:

• Sanitizers like Bromine or a mineral agent
• pH levels, which need to be maintained within a specific range to disrupt bacteria growth
• Alkalinity levels, like pH, must be within a range

If any single one of these is out of alignment, it could lead to issues. 

Since your water is cloudy, the first thing to check is your sanitizer levels. Low sanitizer levels can quickly lead to a buildup of bacteria, algae, and dead organic debris (like skin flakes!), making the water cloudy.

pH and Alkaline levels are typically not the main culprits for cloudy water, but you should check them too to be thorough. Besides, these levels all need to be checked often!

If you are unaware of the need to check the chemical balances in your hot tub, here’s a kit to help you start the process.

If you have cloudy hot tub water but levels are good, then you should check the following.

The spa filter is dirty

As opposed to a chemical sanitizer, mechanical filtration refers to the spa’s actual filter. It filters “mechanically,” i.e., by straining larger clumps of debris or material.

Once you’ve ensured your sanitizer levels are good, pop open the filtration compartment and give your filter a quick check. If it’s full of gunk and debris, it’s time for a quick clean or perhaps even replacement.

An excess of debris on your filter increases the amount of sanitizer your spa needs, quickly leading to low sanitizer levels and a buildup of gunk, causing cloudy water.

Your hot tub has seen more use lately

Hot tubs are meant to be shared, so it’s no wonder they see many people come and go in a day.

However, if you’ve recently had a party, company over, or anything else that resulted in the hot tub getting more use than normal, it’s not uncommon to find cloudy water afterward.

It’s a little gross, and most people don’t like to think about it, but every person who gets in the hot tub is leaving behind:

• Dead skin flakes that all humans are shedding constantly
• Any lotions or oils that they had on their body, even shampoos and conditioners
• Sweat and other fluids that are a natural part of our bodies

Your sanitizer and filtration are set up to deal with this, but if there’s a sudden burst of people coming and going, the water will cloud up from all the gunk it’s trying to filter. It may even have run out of sanitizer to deal with it all.

Can too much chlorine make water cloudy?

We briefly discussed that low sanitizer levels could lead to cloudy water from all the stuff that isn’t being cleaned up, but it goes the other way, too.

High levels of any of the core chemical levels (sanitizer, pH, and alkalinity) can have effects that lead to cloudy water.

This is another reason why it’s important always to monitor your core chemical levels.

How to fix cloudy hot tub water

Now that we’ve discussed the main culprits of your cloudy hot tub water, let’s discuss each one and how to fix it (along with some other tips).

Clear the tub of debris

If you haven’t been using a hot tub cover, now is the time to start.

Never leave a hot tub uncovered when you aren’t using it, even just for a single night, or you could end up with all of this in your water:

• Bugs, and lots of them
• Bird poop
• The urine or poop of whatever creatures decide to investigate your hot tub

That’s just to name a few. Not covering your hot tub will make the water cloudy all the time—a serious health risk—and you’ll also spend lots more on sanitizers and clarifiers.

If your hot tub has much of this in it, you will be better off draining, cleaning and then refilling it.

Clean the filter

If the hot tub filters are very dirty, this can certainly contribute to cloudy spa water.

Cleaning the hot tub filters should be a part of your regular hot tub maintenance schedule. This post will help with the best way to clean hot tub filters.

Fix any incorrect core levels

After just clearing visible debris, the next thing you need to do is run a test on your core levels. If any one of them is out of alignment, fix it by the appropriate method:

• Sanitizer: If it is too low, add more to the recommended level. If it is too high, either remove some water and dilute it with fresh water or use Sodium Thiosulfate to neutralize some of it.
• pH: If it is too high or too low, use soda ash or a pH decreaser, as the instructions on their packaging indicate. There are no shortcuts on this one!
• Alkalinity: Same as pH, you will have to use an alkalinity increaser or decreaser

Keep in mind that pH and alkalinity treatments affect each other. Always fix the alkalinity first before moving on to pH. 

Try a shock treatment

Once you’ve tested the above three, and the water still isn’t clear, it’s time for a good old-fashioned flocculant and shock treatment combo.

A flocculant simply binds all the smaller microscopic particles together so the filter can more easily pick them up. 

The shock treatment then comes in and does exactly what it says. It chemically shocks any algae, bacteria, or other gunk to death so it can be cleaned up better.

Hot Tub Cloudy When Jets Are On

When the jets are turned on in a hot tub, the water can sometimes become cloudy due to a phenomenon known as microbubbles.

When the jets are activated, they introduce a rush of air into the water, agitating it and producing tiny air bubbles. These microbubbles can often cause the water to appear cloudy or milky.

This is a normal and temporary occurrence, and the cloudiness usually dissipates over time as the air bubbles rise to the surface and pop. It is important to note that cloudy water caused by the jets is typically unrelated to the water’s cleanliness or hygiene.

Is it safe to use a cloudy hot tub?

We know it can be a pain to have to do all of this maintenance when you just wanted a nice hot soak but getting into a hot tub with cloudy water may not be safe.

You could get hot tub rash, infections, burns from too much sanitizer, or any number of other issues. Don’t get in your hot tub until you figure out the source of the problem and fix it.

Fixing cloudy spa water summary

When it comes to hot tubs, it can easily seem like there is a never-ending torrent of information to learn about pH levels, sanitizers, treatments, and so much more. When you’re faced with a problem like cloudy water in hot tub, it’s hard to know where to start.

Thankfully, with a little know-how, it can usually be an easy problem to fix. Just check your core levels, clean the filters, and try a shock treatment. If nothing works then empty the hot tub and refill.